Well tool and method of using same



June 22, 1965 R. P. KIRK WELL TOOL AND METHOD 0F USING SAME 3Sheets-Sheet 1 iledk May 5, 1962 -w u .a I=. Z lr r r 6 M 6 INVENTOR.

BY/7 ale/ 4 Y M June 22, 1965 Filed May 5, 1962 R. P. KIRK WELL TOOL ANDMETHOD OF USING SAME 5 Sheets-Sheet 2 /r/fUJ P. /f/r/f INVENTOR.

June 22, 1965 Filed May E, 1962 R. P. KIRK WELL TOOL AND METHOD OF USINGSAME 5 Sheets-Sheet 3 INVEN TOR.

3,190,357 WELL TOUL AND METHD 9E' USING SAW Rufus P. Kirk, dessa, Tex.

(1417 Sherwood Lane, @Mahoma City, Okla.) Fiied May 3, 1962, Ser. No.192,12) 15 `Claims.. (Cl. 16S-44) This invention relates to new anduseful improvements in well tools and methods of using same.

An object of this invention is to provide a new and improved valve for awell pipe which is open to provide for the unloading of mud or otherfluid in the pipe and which is automatically closed to provide for thetlow of the oil or other well fluid after the unloading.

An important object of this invention is to provide a new and improvedmethod for displacing iiuid in a casing annulus and well tubing bycirculating a gas or a liquid lighter than the fluid to be displaced,then closing off such circulation, and producing oil or other well iuidthrough the tubing.

Another object of this invention is to provide a new and improved methodand valve which is adapted to be used in conjunction with one or moregas lift valves for improving the operation of the gas lift valves byproviding a lower liquid level in the casing annulus than is normallyattained in the absence of such valve.

A particular object of this invention is to provide a new and improvedvalve adapted to be positioned in a well tubing longitudinally below alateral opening in the tubing, said valve having a frangible closurewhich is adapted to be fractured upon an upward movement of the valve inthe tubing, whereby the valve closes olf the flow through said lateralopening and opens iiow from said tubing through said valve.

A further object of this invention is to provide a new and improvedmethod and apparatus wherein circulation between a casing annulus and anopening in a well tubing is effected, then such circulation is stoppedby closing such opening, and thereafter such opening is opened again bya well tool to permit a killing of the well, further circulation, orsimilar operations.

The preferred embodiment of this invention will be describedhereinafter, together With other features thereof, and additionalobjects will become evident from such description.

The invention will be more readily understood from a reading of thefollowing specification and by reference to the accompanying drawingsforming a part thereof, wherein an example of the invention is shown,and wherein:

FIG. 1 is a schematic view illustrating the first part of the method ofthis invention wherein the gas is being introduced into the casingannulus for displacing the mud in the annulus and the tubing;

FIG. 2 is a view similar to FG. 1, but showing a further step in themethod of `this invention wherein substantially all of the mud in thecasing annulus and tubing have been displaced by the gas;

FIG. 3 is a viewsimilar to FIG. 1 and FIG. 2, but illustrating the valveof this invention in a closed position for closing off the lateralopening between the tubing and the casing annulus and the subsequentproduction of oil or well uid through the tubing to the surface;

FIG. 4 is a schematic view illustrating a modified form of the method ofthis invention wherein gas lift valves are employed, and wherein a firststage of such method is illustrated with the gas injected into thecasing annulus and operating the upper gas lift valve;

FIG. 5 is a view similar to FIG. 4, but illustrating the modified formof the invention of FIG. 4 wherein the next phase is indicated by thedisplacement of the drilling 3,l9,357 Patented June 22, 1965 mud orother fluid in the annulus and tubing with gas injected from thesurface;

FIG. 6 is a view similar to FIGS. 4 and 5 and illustrates the next phaseof the method of such modified form of the invention, wherein thelateral opening in the well pipe or tubing is closed by the valve andthe gas lift operations are performed by the predetermined gas pressureinthe casing annulus which is introduced through the gas lift valves;

FIG. 7 is a vertical sectional view of the preferred form of the valveof this invention, shown in the position Ifor closing off flow throughthe valve body while permitting flow through the lateral opening of thewell pipe or tubing; and

FIG. 8 is a view similar to FIG. 7, but illustrating the valve in theposition closing the lateral port of the Well pipe or tubing andproviding an opening through the valve body for the flow of oil or otherwell fluid upwardly through the valve body and into the tubing or pipethereabove.

In the drawings, the letter C designates a well casing which is ofconventional construction and which has a well pipe or tubing T therein,with a casing annulus A therebetween. The well pipe or tubing T has alateral opening or openings 10 formed therein, the opening and closingof which is controlled by a valve V, the details of which will beexplained hereinafter. A packer P of conventional construction isdisposed in the casing annulus A below the opening or openings 1t).Briefly, in carrying out the method of this invention using the valve Vof this invention, gas or other iiuid G is introduced into the upper endof the casing C so as to force the drilling mud M or other well fluiddownwardly in the annulus A, through the opening or openings 1li andupwardly in the well pipe or tubing T. Such circulation of the gas Gcontinues until a pressure differential is developed across the valve Vwithin the tubing T which is sufficient to move the valve Vautomatically to a closed position (FIG. 3). When the valve V is in theclosed position, the well fluid W, generally oil, is produced throughthe pipe or tubing T for discharge at the surface S, or through anyother suitable well head equipment. Also, as will be explained inconnection with FIGS. 4-6, the method of this invention may be employedin conjunction with gas lift valves on the well pipe or tubing T.Furthermore, if it is necessary or desirable to open the valve V againafter it has been moved to the closed position, such opening can beaccomplished by the use of a wire line tool sothat the well can bekilled with mud or the like, or othersimilar well operations performed.

Considering now the details of the valve V of this invention, which areshown in FIGS. 7 and 8, such valve V includes a tubular pipe section 12having the openings 10 formed laterally therethrough. Such section 12has an adapter 14 threaded or otherwise secured to its upper end and asecond adapter 15 threaded or otherwise connected to its lower end. Theadapter 14 is connected to a pipe section 16 which extends on upwardlywith' the rest of the pipe or tubing T to the surface S. The adapter 15connects with a tubing section 17 by means of threads or any othersuitable connetcing means so that the tubing string T continues on downbelow the valve V.

The valve V includes a longitudinally movable valve body 20 which has anupper bore 20a and a lower bore 2Gb. The bores 20a and Ztib are of thesame internal diameter and it is to be noted that the thickness of thevalve body 20 extending from such bores 20a and 20h outwardly, togetherwith the thickness of the valve section 12, are approximately the sameas the thicknes of the adapters 14 and 1S and the normal tubing sections16 and 17. Therefore, the valve V of this invention provides a full openbore, as will be enlarging the external diameter of the tubing string T.In circumstances where the enlargement of the tubing more fullyexplained, without string at the valve V is not undesirable, thethicknesses ofv the valve section 12 and thek body 20 may be increased.

The valve body 20 has a lower yannular extension 29C' which ts into anannular slot a atV the upper end of' the adapter 15. lSuitable shearApins 25 extend through the i valve body 20, as will be more evidenthereinafter. Suita,

ble lexternal seal rings 26 at the lower end and 27 Vat the upper endare provided for sealing on both the upper and lower sides of theopenings 10 when the valve bodyv isin the positionfor closing suchopenings 10 (FIG. 8). f v

The body 20 is provided with an annular external recess 20d above theO-rings 27, which recess 20direceive's a split metallic lock ring 30.Such 'ring 30 is confined in a compressed condition when the valvebodyy20 is in the lower position shown in FIG. 7, but is expanded by itsown resilience to the position shown in FIG. 8 when the valve body 20has moved upwardly to closejthe openings or ports 10. Such lock ring 30retainsthevalve body 20 in the upper position of FIG. 8 even after thewell fluid pressure differential has ceased to act in an upwarddirection on the body 20. A seal ring 28 'which is alsoA of rubber andpreferably an,O-ring,is located above the lock ring 30 to reduce theVamount of corrosive fluids' which might otherwise reach the lockring30.

The valve body 20 has an annular lateral shoulder 20eV 'Y formed abovethe bore 20a for receiving a closure disk'31.

The peripheral edges of the disk 31 are in contact with body 20 as shownin FIG. 7. YThe closurefdisk orl plate 31 may be made of anysuitableffrangible material such as tempered glass or ceramic material.The material must' be sufficiently strong to withstand the pressureAdifferential acting thereacross, but at the same time it'must shatterfluid.

Vbelow the bore`12a. 31 are indicated by the designation 31a in FIG. 8to indif for the ow'of fluid `through the valve body or sleeve 20 to theupper portion of the tubing T. .The lock ring 30 expands to the positionshown in FIG. 8 within the enlarged diameter 12a to hold or lock thebody or sleeve 20 in the upper position, bythe frictional engagementwith the internal surface of the bore 12a, and also by a contact withthe inclined annular surface 12b formed The fragments ofk the closuredisk cate that suchfragments 31a'are moving with'the well It should bepointed out that the upper surface i31b (FIG. 7.) of the disk 31 ispreferably coated with a layer of rubber orsimilar material whichfwillresist Vabrasion or Sandblasting action caused by-thev circulation ofmud or other fluid prior to the breaking-,of the disk 31. A similarcoating 31C mayr also be providedon the lower Y surface of thevdiskl,although it-'generally is not as desirable or necessary. l i v y v -Incarrying out the method of this inventionas particularly illustrated inFIGS; 1 3, the tubing T is initially positioned-in the casing C withVthe packer P inV position as shown in FIG. l. The valve V is loweredrwith the tubing string `T and is Ysecured in its lower position (FIG.`7) byl means ofthe. shear pins 25. f The shear pins are set atthe-timeof assembly so as to shearv or sever i the body 20 andthe closure plate31.

vao

The pins 25 are of such strength that the pressure of the oil or otherwell fluidW belowr the valve V, minus'the pressurerof the gas Gintroducedr into the casing annulus A will sever'br shear suchpins 25.`In order to provide some flexibility in the amount of force necessarytoshear the pins V25, they can'berrnade so that they will shear at thepressure kof theV oil or well uid Then, if the gas pressured G is toohigh so that thepressure differential between the well uid and the gasis not suiiicient to sever .the pins 25, the ygas pressure can be bledolf to as low to small .pieces whenffractured to open flow throughthevalve body 20,7as' will be more fully explained. l In order to providefor the movement of the valvebody 20 downwardly from the positionYclosing'the Aports 10" as shown in FIG. 8y to the position opening theports 10 as shown in FIG. 7, it is desirable to provide a central boresection 20]c of an increased internal diameter as compared to the boresections 20a and 20h. Such en'- larged bore section 20jc provides for alower lateral shoulder 20g which is adapted to be contacted byv a con! ythereto as shown in FIG. 2 before thepins 25v shear. Such ventional wireline operated well tool shown" in dotted lines and indicated by theletter R in FIG., 8. e

The valve section 12 is formed with an enlarged internal diametersection 12av at its upper end so that the-split ex-Y pansible ring may`expand outwardly as shown in FIG. 8 to hold or lock the sleeve 20iri`the upper position. v

VThe adapter 14 has a plurality ofv sharp pointed pro- Jecnons 14a whichare adapted to contact the closure diskV or plate 31-as the valve bodyor-sleeve 20 moves upwardly by the action of the fluid pressureYdifferential withinf the Well. Such projections 14a cause a fracturingofY as atmospheric pressurein order to create an adequate pressurevdifferential across the body 20 and the closure 31.

In any event,'after the tubing T has been positioned as shown in' FIG.yl with theY packer P below the lateral openings 10,l the gas Gy orotherfluid lighter in density than the mud M is introduced at theupperend of the 'c annulus Av through any suitable well head equipmentschematically indicated at C. Such gas G displaces the mud downwardly inthe annulus-A through the lateral openings 10 and then `upwardly in thetubing T for d ischarge through the surface outlet S; Since the mud isof a greater density than the gaslor other'fluid G, the pressuredifferential acting across-the valve body 20 and the closure plate 31 issmaller with the'mudnthan with they gas. Preferably, theV gas G fullydispla'ces themud M, or atleast the gas/G reaches the level G or onesimilar pins 25 shear automaticallyr when the pressuref differentialactingacross ythe valve Vbody 21V/is sufficient to sever the pins 25.The valve body 20.v is then moved upwardly by the pressure differentiallso that the closure plate or disk 31 hits the projectionsla with a bloworl impact sufficient to crack vor shatter the material of the plate ordisk; 31 into small particles 31411116. 8),. vTher well fluid is thuscapable of flowing upwardly through the bore of the body 20 intfo'thetubing T thereabove. Inl the usual case, the particles 31a are carriedupwardly with the well fluid and are discharged at the upper.v surfaceoutletS.

When the valve body 20. has` moved kupwardly to the closed position, theseal rings 2,6.and 27 span the openings 10. The 'gas G is thus confinedin the annulus A, and preferably the inlet line, C is `closed with avalve or other suitable means'X (FIG. 3).

- Y Thus,.. with the method of this invention asY described above and asillustrated in'FIGS. 1-3., the mud or other well fluid-is displaced fromthe annulus and the tubing after the packer P is set, causing the wellto iiow with the oil or other well fluid without the use of swabbing orwire line operations inside the tubing. Also, the dangers inherent inunloading a well before setting the packer are eliminated with thisinvention.

The gas G is preferably nitrogen or methane, but other gases may beused. Also, a light density uid such as water, which has a lighterdensity than the usual mud M in the Well, may be used in place of thegas G. So long as the gas or other fluid G has a light enough density tocause a suicient unloading of the mud M to reduce the pressure above thevalve V so as to develop a pressure differential across the valve Vsufficient to sever the shear pins 25, it will suffice for the purposeof this invention.

In the form of the invention shown in FIGS. 4-6, gas is used as theprimary unloading liuid since gas lift valves indicated schematically atF-1, F-2 and F-3 are preferably used with such form of the invention. Itwill be understood that although only three gas lift valves areillustrated in FIGS. 4-6, additional valves may be ernployed, dependingupon the usual spacing and production requirements. Even though the gaslift valves are employed in the modified form of the invention shown inFIGS. 4-6, the method as described in connection with FIGS. 1-3, and theoperation of the valve V are basically the same. Thus, the gas G orother uid which is lighter than the mud M is introduced .at the wellhead connection C to the annulus A for unloading or displacing the mud Mfrom the annulus A and the tubing T. The valve V is in the lowerposition wherein the ports are opened during such circulating orunloading of the mud M from the tubing T. During such unloading, the gaslift valves may function to introduce or inject gas into the tubing Tbefore the level of the gas G has reached the lateral openings or ports10, but such action of the gas lift valves is not necessary until afterthe gas G has completely unloaded the annulus A and has at leastpartially unloaded the tubing T.

When the pressure differential acting across the valve body and theclosure disk or plate 31 reaches the predetermined value necessary toshear the pins 25, the valve body 20 moves upwardly to the positionshown in FIG. 8 and closes the ports 10.

With the valve V in the closed position, closing the ports 10 and withthe disk 31 shattered to allow the well fluid W to flow upwardly throughthe body 20 and into the tubing T, the usual production techniques withthe gas lift valves are then employed. However, the gas lift valvesoperate more satisfactorily with the present method and apparatusbecause the presence of the gas at the point below the lowest of the gaslift valves is assured with the present invention. The present method,when used in con junction with the gas lift valves, makes it possible towork the lowest gas lift valve which is set to open at the gas pressurein the annulus A, and minimizes problems in gas lift production such asimproper valve spacing, emulsion formation, and differentials in liquidlevels in the tubing and annulus. The pressure of the gas G in theannulus A is maintained for continuous ow lifting or controlled forintermittent or slug lifting through the inlet valve X or other suitablemeans so that the gas injection into the tubing T is thereby controlledafter the valve V has moved to the position shown in FIG. 6.

Other advantages in addition to those enumerated above will occur tothose skilled in the art in connection with the use of the presentinvention in conjunction with the gas lift valves as shown in FIGS. 4-6.It will also be appreciated that this invention may be used in dualproduction lines.

The foregoing disclosure and description of the invention isillustrative and explanatory thereof and various changes in the size,shape and materials, `as well as in the details of the illustratedconstruction, may be made within the scope of the appended claimswithout departing from the spirit of the invention.

What is claimed is:

1. A valve adapted to be mounted in a well pipe having a lateral openingtherethrough, comprising:

(a) a tubular valve body mounted in said well pipe for longitudinalmovement relative to said pipe,

(b) closure means carried by said body for closing off fluid flow fromsaid pipe through said valve body,

(c) retaining means releasably retaining said valve body in an openposition in said pipe permitting uid ow through said lateral opening,

(d) said retaining means being releasable upon the application of apredetermined fluid pressure differential acting on said closure meansfor moving said body longitudinally in said pipe to close said lateralopening, and

(e) opening means for engaging said closure means upon the longitudinalmovement of said valve body for opening said closure means andpermitting iow through said body from said pipe.

2. The structure set forth in claim 1, wherein (a) said closure means isfrangible into relatively small pieces, and

(b) said opening means for engaging said closure means includes meansfor fracturing said closure means upon the longitudinal movement of saidvalve bodyrelative to said pipe.

3. A valve adapted to be mounted in a well pipe having a lateral openingtherethrough, comprising:

(a) a tubular valve body mounted in said well pipe for longitudinalmovement relative to said pipe,

(b) closure means carried by said body for closing off iiuid dow fromsaid pipe through said valve body,

(c) retaining means releasably retaining said valve body in a positionpermitting liuid dow through said lateral opening,

(d) said retaining means being releasable upon the application of apredetermined fluid pressure differential acting on said closure meansof said valve body for moving said body longitudinally in said pipe toclose said lateral opening, and

(e) means for opening said closure means upon the longitudinal movementof the valve body for permiting fluid ow in the well pipe.

4. The structure set forth in claim 1, wherein said retaining means is.a shear pin connecting said valve body to said pipe and adapted toshear when said predetermined fluid pressure differential is developed.

5. The structure set forth in claim 3, wherein said retaining means is ashear pin connecting said valve body to said pipe and adapted to shearwhen said predetermined fluid pressure differential is developed.

6. The structure set forth in claim 3, including seal means between saidvalve body and said well pipe for inhibiting fluid ow downwardly aroundsaid valve body when said valve body is in said open position, wherebyfluid may be circulated between the interior yand exterior of said pipethrough said lateral opening above said seal means and said closuremeans.

7. In combination with a well pipe in a well casing wherein the annulusbetween the casing and the pipe is packed olf with a packer, and whereinthe pipe has a lateral opening therethrough above the packer, theimprovement residing in a valve, comprising:

(a) a tubular valve body mounted in said well pipe for longitudinalmovement relative to said pipe,

(b) closure means carried by said body for closing off fluid iiow fromsaid pipe through said valve body,

(c) retaining means releasably retaining said valve body in a positionpermitting uid flow through said lateral opening,

(d) said retaining means being releasable upon the application of lapredetermined uid pressure differen-` tial acting on said closure meansof said valve body 7 for moving said body longitudinally in said pipetovclose said lateral opening, and (e) means for opening said closure meansupon the longitudinal movement of the valve body for permitting uid flowin the well pipe. v 8. In combination with `a well pipe in a well casingwherein the annulus between the casing and the pipe is packed o with apacker, and wherein the pipe has a later-al opening therethrough abovethe packer, the irnprovement residing in -a lv-alve, comprising:

(a) a tubular valve body mounted in said well pipe forlongitudinalmovement relative to said pipe, (b) closure means carried bysaid body for closing oft iiuid ilow from said pipe through said valvebody,

(c) retain-ing means releas-ably retaining said valve` body in an openposition in said pipe permitting fluid iiow through said 'lateralopening,

(d) said retaining means being releasable upon the application of apredetermined fluid pressure differentialncting on said closure meansfor movin-gsai-d (a) closing o." fluid tlow downwardly through thetubing below the later-al opening, t

(b) circulating a iluid downY the casing annulus and through saidlateral opening lfor now upwardly in said tubing to thereby displace thefluid previously in the annulus and tubing with a lighter density fluid,

(c) developing a predetermined `iluid pressure differential across theclosed oi portion of the tubing sui-v cient to effect an opening of thetubing, and (d) closing said lateral opening in response to saidiiuidgpressure differential to discontinuelcirculation trom the annulusto the tubing wlhile enabling Well 'fluid .to be produced through thetubing.

10. Incombination with a well pipe in a well casing wherein the :annulusbetween the casing and the pipe is packed off with laY packer, 'whereina plurality of longitudinally spaced gas lift valves are mounted on thewell pipe in the annulus, and wherein the pipe has a lateral opening ata point below said gas lift valves and above the packer, the improvementresiding in a valve, oom-k prising:

(a) a tubular valve body mounted in said well pipe'for longitudinalmovement relative to said pipe, (b) closure means carried by said bodytor clos-ing oit iiuid tlow from said pipe through said valve body,(c),retaining means .releasabily retaining said |valve body in aposition permitting fluid ilow through said lateral opening,

(d) said retaining means being releasableupon the application of lapredetermined iluid pressure diiferen-- tial acting on lsaid closuremeans of said valve body for moving said body longitudinally in saidpipe t close s-aid lateral opening, and t (e) means vfor' openingsaid'closure means upon the longitudinal movement Aof the valve bodyIfor permitting uid flow in the well pipe.

11. E1n combination `with a well pipe in a well casing wherein theannulus, between the casing and the'pipe is packed oli with a packer,wherein a plurality of longitudinally spaced gas lift valves are mountedon the vwell pipe in the annulus, and wherein the pipe has a` lateralopening Vvat a point below said gas lift valvesvand above said packer",the improvementresiding ina valve, compris-ing;

(a) a tubular valve body mounted in said wall pipe for longitudinalmovement relative to said pipe,

(b) t closure means carried by said bodyfor closing olf fluid ilow fromsaid pipe throughsaid valve body,

(c) retaining means releasably. retaining said valve body inY an openposition in said pipe permitting iluid flow through said,v lateralopening,

(d) ,said'retaining meansbeing releasable -upon the application of apredetermined fluid pressure differential acting on'said closurel meansfor moving said body longitudinally in said pipe to close said lateralopening, and v (e) opening means t'or engaging said closure means uponthe longitudinal moi/'ementy of said valve body for opening said closuremeans Iand permitting llow through said body from said pipe.

i12. A method of producing well `fluid throughr a tubing in a wellcasing, wherein the annulus between the tubing and the casing is packedoit with a packer, wherein a plurality ot longitudinally spaced gas liftvalves are mounted on the well pipe in the annulus, and wherein thepipe'has a later-al opening below said gas'lift valves and above thepacker, comprising the steps of:v

(a) closing oit vfluid iiow downwardly through the tubing below thelateral opening,

(b) circulating a gas down the casing annulus and through said lateralopening for tlow upwardly in said tubing Yto thereby displace the gaspreviously in the annulus and tubing with a lighter :dens-ity gas,

(c) developing a predeterminedl fluid pressure differential across theclosed ott portion ofthe tubing suil cient to eiect an opening of thetubing,

(d) thereaftervclosing said Vlateral opening in said tubing todiscontinue the circulation ,from the annulus to the tubing, and

(e) then producing oil through said tubing.

'k 13. A method of producing well uid throughfa tubing in a -welleasing, wherein the annulus between the tubing and the casing is packedoit with a packer, wherein a plurality of longitudinally spaced gas liftvalves are mounted on the well pipe in the annulus, and wherein the pipehas a lateral opening below said ga-s lift val-ves land above thepacker, comprising the steps of;

(a) closing off tluid flow downwardly through the tubing below thelateral opening,

l(b) :circula-ting a gas down Ithe casing annulus and through :saidlateral opening tor flow upwardly in said tubing to thereby displaceythe gas previously in the :annulus and tubing with a lighter densitygas,

(c) developingr a predetermined fluid pressure differential across theclosed off portion of the tubing sufii- 1 'cient to effect an opening ofthe tubing,

(d) ythereafter closing said lateral opening in said tubing todiscontinue the circulation from the annulus to the tubing, and Y (e)then producing oil through .said tubing while controllingtthe gaspressure in Said Lannulus for gas injection into s-aid well pipe throughsaid gas lift valves to etect a gas lift ofthe oil. l

14. A valve adaptedto be mounted in a well pipe hav-v ing a lateralopening therethrough, comprising:v

l (a) a tubular valve body mounted insaid well pipe for longitudinalmovementrelative to said pipe,.

(b) closure means carriedby said body for closing oit iluid ilow fromsaid pipe through said yalve body,

(c) retaining means releasably retaining said ,-valve body in a positionpermit-ting duid ilow through said lat-eral opening,

(d) said retaining means being releasable upon the application of apredetermined uid 'pressure differential acting on said closure means ofsaidvalve body for moving said body longitudinally in said'pipe to closesaid lateral opening, Y

(e) means on said lbody engageable by a tool lowered E in said pipe foreffecting a longitudinal movement of said body to `open said lateralopening, `and (f) means for opening said closure means upon thelongitudinal movement of the valve body for permitting lluid ow in thewell pipe.

15. A method of producing Well fluid `through a tubing in a Well casing,wherein the iannulus between the tubing and the `casing is picked yoffwith `a packer and wherein the tubing has a lateral open-ing above thepacker, comprising the steps of:

a) closing 01T uid flow downwardly through the tubing below the lateralopening,

(b) circulating :a uid down the casing annulus and through said later-a1opening for flow upwardly in said tubing to thereby displace the uidpreviously in the annulus and tub-ing with a lighter density lluid,

(c) developing a predetermined duid pressure differential across theclosed `off portion of the tubing sufficient :to eifect an opening ofthe tubing,

(d) thereafter closing said lateral opening in said tub- 2 ing todiscontinue the circulation from the annulus to the tubing,

(e) then producing well iluid through vsaid tubing, and (if)subsequently again opening said lateral Opening for killing the well andsimilar operations.

References (Jited by the Examiner UNITED STATES PATENTS 7/25 5/30 lll/368/4() 1/43 2/44 9/60 2/62' 4/62 1/63 6/63 3/64 Arbon 166-45 X Sawyer166-44 Wells 166-68 X Brown 166-224 Baylor 166-67 Lloyd 166-45 X Garrett166-45 X Tausch 166-44 X Moller 166-224 Murr-ay 166-224 X Alley 166-224X Graham 166-224 X CHARLES E. OCONNELL, Primary Examiner.

9. A METHOD OF PRODUCING WELL FLUID THROUGH A TUBING IN A WELL CASING,WHEREIN THE ANNULUS BETWEEN THE TUBING AND THE CASING IS PACKED OFF WITHA PACKER AND WHEREIN THE TUBING HAS A LATERAL OPENING ABOVE THE PACKER,COMPRISING THE STEPS OF: (A) CLOSING OFF FLUID FLOW DOWNWARDLY THROUGHTHE TUBING BELOW THE LATERAL OPENING, (B) CIRCULATING A FLUID DOWN THECASING ANNULUS AND THROUGH SAID LATERAL OPENING FOR FLOW UPWARDLY INSAID TUBING TO THEREBY DISPLACE THE FLUID PREVIOUSLY IN THE ANNULUS ANDTUBING WITH A LIGHTER DENSITY FLUID, (C) DEVELOPING A PREDETERMINEDFLUID PRESSURE DIFFERENTIAL ACROSS THE CLOSED OFF PORTION OF THE TUBINGSUFFICIENT TO EFFECT AN OPENING OF THE TUBING, AND (D) CLOSING SAIDLATERAL OPENING IN RESPONSE TO SAID FLUID PRESSURE DIFFERENTAIL TODISCONTINUE CIRCULATION FROM THE ANNULUS TO THE TUBING WHILE ENABLINGWELL FLUID TO BE PRODUCED THROUGH THE TUBING.